JP2010537925A - Glass melting method - Google Patents

Abstract

  The present invention relates to a method for burning pulverized fuel as a heat source to melt a raw material for producing glass. The method supplies a controlled flow of a mixture of pulverized fuel and air or gas under pressure for pneumatic transfer in the distribution means, and distributes the mixture of pulverized fuel and air or gas from the supply means. The mixture of pulverized fuel and air or gas that is discharged from the distribution means and directed to each of the plurality of burners in the glass melting region of the glass melting furnace in a controlled manner, and the glass melting of the glass melting furnace Burning pulverized fuel with burners in the zone while providing a burning flame with high thermal efficiency to provide controlled heating for melting the glass, refractory material erosion and wear action of the pulverized fuel in the glass melting furnace Weaken. Examples of the refractory material include silica-alumina-zircon, magnesite, chromium-magnesite, magnesia-alumina spinel, alumina-silicic acid, zircon-silicic acid, magnesium oxide and the like.

Description

  The present invention relates to a glass melting method. More specifically, the present invention relates to a method for melting glass using a pulverized fuel.

  Glass melting is performed in various types of furnaces and fuels, depending on the final properties of the product, taking into account the thermal efficiency of the melting and refining processes. Unit melting furnaces are used to melt glass (by gas fuel). Such a furnace has a plurality of burners along the side of the furnace. The entire unit is similar to a closed box with a chimney. The chimney can be placed either at the starting feeder or at the downstream end of the furnace in the downstream direction. However, high temperature operation furnaces where glass comes out have very large heat losses. For example, at 1370 ° C. (2500 ° F.), the flue gas heat is 62 percent of the heat input to the natural gas combustion furnace.

  In order to utilize the residual heat of the flue gas, a complicated and expensive design called a regenerative furnace has appeared. In order to operate the glass melting regenerative furnace, a plurality of gas burners are connected to a pair of hermetic regenerators arranged side by side. Each regenerator has a lower chamber, a refractory structure above the lower chamber, and an upper chamber above the structure. Each regenerator has a port connecting each upper chamber to the melt purification chamber of the furnace. The burner is configured to burn fuel such as natural gas, mineral oil, heavy oil, other gaseous fuels or liquid fuels. The fuel is suitable for use in a glass melting furnace and supplies heat for melting and refining the glass raw material in the chamber. The melt refining chamber is supplied with glass raw material at one end where the dog house is located, and has a melt distributor at the other end. The melt distributor includes a series of ports through which molten glass is removed from the melt purification chamber.

  The burner can be installed in several possible configurations. For example, there is a through port configuration, a side port configuration, or an underport configuration. Fuel, such as natural gas, is supplied from the burner into the incoming stream of preheated air coming from each regenerator during the combustion cycle. The resulting flame and the combustion products produced in this flame spread across the surface of the molten glass and transfer heat to the glass in the melt purification chamber.

  During operation, the regenerator alternates between the combustion air cycle and the exhaust heat cycle. Depending on the particular furnace, the flame path is reversed every 20 or 30 minutes. The purpose of each regenerator is to store exhaust heat that enables high efficiency and high flame temperature, as is the case with cold air.

  To operate the glass melting furnace, the feed fuel and feed combustion air to the burner are controlled by measuring the amount of existing oxygen and combustible material at the port mouth and top of the structure. This can ensure that the feed combustion air does not fall below the amount required for complete combustion of the feed fuel at multiple points within or along the melt chamber.

  In the past, the fuel used to melt glass was heavy oil obtained from petroleum distillation. This type of fuel has been used for many years, but this type of heavy oil contains impurities from crude oil such as sulfur, vanadium, nickel and other heavy metals. It has been demanded. This type of heavy oil produces pollutants such as SOx, NOx and particulates. In recent years, the glass industry has used natural gas as a clean fuel. All heavy metals and sulfur entering the liquid stream of petroleum residues from distillation are not contained in natural gas. However, the high temperatures generated in natural gas flames were extremely effective in producing more NOx than other pollutants. In this sense, much effort has been made to develop a low NOx burner to ignite natural gas. Furthermore, various techniques have been developed to prevent the generation of NOx. One example is oxyfuel technology that substitutes oxygen for the air for the combustion process. This technique is disadvantageous in that it requires a unit melting furnace with specially prepared refractories since air penetration must be avoided. The use of oxygen also produces a hot flame, but in the absence of nitrogen, the production of NOx is greatly reduced.

  Another disadvantage of the oxyfuel process is the cost of oxygen itself. In order to reduce the cost, it is necessary to place an oxygen plant near the furnace to supply oxygen necessary for the melting process.

  However, the continued surge in energy costs (primarily natural gas) has forced major float glass manufacturers to add “additional charges” to the number of glass sheets in the truck. Natural gas prices far exceeded previous estimates and have been over 120% this year (in Mexico alone or in other countries).

  The overall agreement among the industry players in the glass industry could have forced wholesalers to monitor these new "surcharges" and be forced to accept those "surcharges" Will be the highest.

  In view of the prior art, the present invention relates to applying various techniques to reduce melting costs using solid fuel derived from petroleum residues in distillation columns. For example, petroleum coke is used to produce environmentally clean glass.

  The main difference of this type of fuel to heavy oil and natural gas is in the physical state of the material, since heavy oil is in the liquid phase and natural gas is in the gas phase, for example petroleum coke is solid. Heavy oil and petroleum coke both have the same type of impurities because they are both derived from the petroleum residue of the crude distillation column. The major difference is in the amount of impurities contained in each. Petroleum coke is produced in three different types of processes called delayed processes, fluid processes and flexi processes. Residue from the distillation process is placed in a drum and then heated from 482 ° C. to 537 ° C. (900 ° F. to 1000 ° F.) for up to 36 hours, removing most of the residual volatiles from the residue. . Volatile material is extracted from the top of the coke drum, and the residual material in the drum is a hard rock consisting of about 90 percent carbon and all impurities from the crude oil used. The rock is extracted from the drum using a hydraulic drill and water pump.

  A typical composition of petroleum coke is about 90% carbon, about 3% hydrogen, about 2-4% nitrogen, about 2% oxygen, about 0.05-6% sulfur, and about 1% other components. .

Use of petroleum coke Petroleum solid fuel is already used in the cement and thermal power industries. According to Pace Consultants Inc., the use of petroleum coke in 1999 was 40% and 14% for cement and thermal power, respectively.

In both industries, the combustion of petroleum coke is used as a direct combustion system. In a direct combustion system, the atmosphere produced by the combustion of fuel is in direct contact with the product. For cement production, a rotary kiln is required to give the product the required temperature profile. In this rotary kiln, a molten cement shell is always formed to prevent the kiln from being attacked by direct contact between the combustion gas and flame and the refractory of the kiln. In this case, the calcined product (cement) absorbs the combustion gas and prevents the erosion and wear effects of vanadium, SO ₃ and NOx in the rotary kiln.

  However, because of the high sulfur and vanadium content, the use of petroleum coke as fuel is not common in the glass industry. It is also caused by adverse effects on refractory structures and environmental problems.

Problems with refractories Several types of refractory materials are used in the glass industry. Most of these are used to achieve different functions. Its functions include not only thermal conditions but also chemical resistance and mechanical erosion due to impurities contained in the fossil fuel.

  The use of fossil fuels as the main energy source means that various types of heavy metals contained in the fuel, such as vanadium pentoxide, iron oxide, chromium oxide, cobalt, etc., are introduced into the furnace. Most heavy metals evaporate during the combustion process. This is because the vapor pressure of the metal oxide is low and the temperature of the melting furnace is high.

  The chemical properties of the flue gas coming out of the furnace are usually acidic because of the high sulfur content from fossil fuels. Vanadium pentoxide also exhibits acidic behavior like sulfur flue gas. Vanadium oxide is one of the metals that represents a source of damage to basic refractories. This is because the oxide behaves acidic in the gaseous state. It is well known that vanadium pentoxide reacts violently with calcium oxide to form dicalcium silicate at 1275 degrees Celsius.

  Dicalcium silicate continues to be damaged until it forms a melwinite phase, a montericite phase, and finally a forsterite phase. The forsterite phase reacts with vanadium pentoxide to form low melting point vanadium tricalcium.

  The only way to reduce the damage caused to the basic refractory is to reduce the amount of calcium oxide in the main basic refractory and to continue reacting with vanadium pentoxide until the refractory is destroyed. It is to prevent the production of calcium.

  On the other hand, the main problem with the use of petroleum coke relates to the high sulfur and vanadium content that adversely affects the refractory structure in the furnace. The most important property required for a refractory is its resistance to exposure to high temperatures for extended periods of time. In addition, it must be able to withstand rapid changes in temperature and be resistant to the erosion of molten glass, the corrosive action of gases, and the wear of particles in the atmosphere.

  The effect of vanadium on refractories has been described in various papers, namely The Glass Industry Magazine, November 1978 and December Roy W. Brown and Karl H.H. A study by Sandmeyer, "Influence of sodium vanadate on superstructure refractories", studied in parts 1 and 2. In this paper, researchers are working on fluid casting compositions such as alumina-zirconia-silica (AZS), α-β alumina, α-alumina, and β-alumina that are commonly used in glass tank superstructures. Various cast refractories centered to overcome vanadium erosion therein were tested.

  J. et al. R. McLaren and H.M. M.M. The article by Richardson, "The effect of vanadium pentoxide on aluminum silicate refractories" describes a series of experiments. Conical deformation was performed on a set of ground samples from bricks having an alumina content of 73%, 42% and 9%. Each sample contains a vanadium pentoxide admixture alone or in combination with sodium oxide or calcium oxide.

  Discussion of these results focused on the action of vanadium pentoxide, the action of vanadium pentoxide and sodium oxide, and the action of vanadium pentoxide and calcium oxide. The conclusion is as follows.

  1. Mullite withstood the action of vanadium pentoxide at temperatures up to 1700 ° C.

  2. There was no evidence of formation of a crystalline composition, a solid solution of vanadium pentoxide and alumina, or a solid solution of vanadium pentoxide and silica.

  3. Vanadium pentoxide may act as a mineralizer with oil ash during slag formation of aluminosilicate refractories, but this is not the main slag former.

  4). A low melting point compound is formed by vanadium pentoxide and sodium oxide or calcium oxide. In particular, it is formed by vanadium pentoxide and sodium oxide.

  5. In the reaction of sodium vanadate or calcium vanadate with aluminosilicate, low melting slag is formed in bricks rich in silica rather than bricks rich in alumina.

The 20th volume of T.G. in the April 1979 issue of Glass Technology. S. Busby and M.C. In a paper by Carter “Effects of SO ₃ , Na ₂ SO ₄ and V ₂ O _{5 on} Bonded Minerals of Basic Refractories”, some spinel and silicates that are bonded minerals of basic refractories are Both were tested in a sulfur atmosphere at 600-1400 ° C. with and without the addition of Na ₂ SO ₄ and V ₂ O ₅ . It was found that certain MgO or CaO in these minerals changed to sulfate. The reaction rate was increased by the presence of Na ₂ SO ₄ or V ₂ O ₅ . These results show that CaO and MgO in basic refractories can be converted to sulfate when used in a furnace where sulfur is present in the exhaust gas. The formation of calcium sulfate occurs below 1400 ° C., and the formation of magnesium sulfate occurs below about 1100 ° C.

  However, as described above, the influence of vanadium on the refractory material has caused many problems in the glass heating furnace, which have not been solved as a whole.

Petroleum coke and the environment Another problem with the use of petroleum coke relates to the environment. The combustion of petroleum coke has caused environmental problems due to the high content of sulfur and metals such as nickel and vanadium. However, progress already exists to reduce or desulfurize petroleum coke with high sulfur content (greater than 5% by weight). For example, on June 21, 1983, Charles P. U.S. Pat. No. 4,389,388 issued to Goforth relates to the desulfurization of petroleum coke. Petroleum coke is treated to reduce the sulfur content. The ground coke is contacted with heated hydrogen under a pressurized condition for a residence time of about 2 to 60 seconds. Desulfurized coke is suitable for metallurgical or electrode applications.

U.S. Pat. No. 4,857,284 issued August 15, 1989 to Rolf Hauk relates to a process for removing sulfur from the exhaust gas of a reducing blast furnace. This patent describes a novel process for removing sulfur contained in a gaseous compound by absorbing it from at least part of the exhaust gas of a reduction blast furnace for iron ore. The exhaust gas is first cleaned with a scrubber, cooled and then desulfurized. During the desulfurization, the sulfur absorbing material is partially constituted by sponge iron generated in the reducing blast furnace. Desulfurization is preferably performed at a temperature in the range of 30 ° C to 60 ° C. Desulfurization is preferably performed in CO ₂ separated from the blast furnace gas and in the blast furnace gas portion used as the carry-out gas.

  U.S. Pat. No. 4,894,122, issued to Arturo Lazcano-Navarro et al. On January 16, 1990, desulfurizes petroleum distillation residues in the form of coke particles having an initial sulfur content greater than about 5 wt. On how to do. Desulfurization is performed by continuous electrothermal treatment based on a plurality of fluidized beds connected in sequence. Coke particles are continuously introduced into the fluidized bed. The exotherm necessary to desulfurize the coke particles is obtained by using the coke particles in each fluidized bed as electrical resistance. A pair of electrodes extending into the fluidized coke particles are provided, and a current is passed through the electrodes and the fluidized coke particles. After a final fluidized bed without electrodes is provided and the sulfur level is reduced to less than about 1% by weight, the desulfurized coke particles are cooled.

  On November 9, 1993, Richard B. US Pat. No. 5,259,864 issued to Greenwalt, a method for treating environmentally unfavorable materials consisting of petroleum coke and sulfur and heavy metals contained therein, and making molten iron or semi-finished steel It relates to both the fuel for the process and the method of supplying reducing gas to the melter. The molten gasifier has an upper fuel supply end, a reducing gas discharge end, a lower molten metal / slag collection end, and means for providing an inlet for supplying iron into the molten gasifier. The method includes introducing petroleum coke into the melter gasifier from the upper fuel supply end, and blowing oxygen-containing gas into the petroleum coke to form at least a first coke particle fluidized bed from the petroleum coke; The introduction of iron material into the melter and gasifier through the inlet means, the reaction of petroleum coke, oxygen and particulate iron material causes most of the petroleum coke to burn, reducing gas and heavy metals released by the combustion of petroleum coke. Producing molten iron or semi-finished steel containing and producing slag containing sulfur liberated by combustion of petroleum coke.

  An additional factor to consider in the glass industry is the control of the environment, mainly air pollution. The melting furnace contributes over 99% of both particulates and gaseous contaminants in the total emissions from the glass plant. The fuel exhaust gas from the glass melting furnace mainly comprises carbon dioxide, nitrogen, water vapor, sulfur oxide and nitrogen oxide. The exhaust gas released from the melting furnace mainly consists of combustion gas generated by the fuel and gas resulting from the melting of the batch depending on the chemical reaction occurring within this time. The proportion of batch gas from the furnace heated by the flame alone corresponds to 3-5% of the total gas volume.

  The ratio of air pollutants in the fuel exhaust gas depends on the type of ignition fuel, its calorific value, combustion air temperature, burner design, flame configuration, and excess charge. The sulfur oxides in the exhaust gas of the glass melting furnace are produced from the fuel used and the molten batch.

  Various mechanisms including volatilization of these metal oxides and metal hydroxides have been proposed. In any case, 70% or more of the substance is known to be a sodium compound, about 10% to 15% is a calcium compound, and most of the remainder is magnesium, iron, silica, and alumina. That is.

Other important considerations in the glass melting furnace is the emission of SO _2. The emission of SO ₂ is due to the sulfur introduced into the raw material and fuel. For example, a large amount of SO ₂ is released within the furnace heating time after the increase in production level. Discharge rate of the SO ₂ spans approximately 1.13kg per ton of the molten glass (2.5 lbs) of ton 2.27 kg (5 lbs). SO ₂ concentration in the exhaust gas is generally in the range of 100~300ppm to the molten natural gas. Using a high sulfur fuel adds approximately 1.81 kg (4 pounds) of SO ₂ per ton of glass for every 1% of sulfur in the fuel.

On the other hand, the production of NOx as a result of the combustion process has been studied and several authors (Zeldovich, J., Acta. Physiochem., Vol. 21 (4), 1946, “Nitrogen oxidation during combustion and explosion”). , Ann Arbor Science Publishers, 1974, page 39, Edwards, JB, "Combustion: Micronuclide Formation and Emission"). These are their reports on “NOx emissions from the glass manufacturing industry”, including uniform NOx formation by Zeldovich and the presentation of empirical formulas by Edwards. Approved by. Zeldovich has developed rate constants for the production of NO and NO ₂ as a result of the high temperature combustion process.

  Finally, under normal operating conditions where the flame is properly controlled and the furnace is not depleted of combustible air, little CO or other residue resulting from incomplete combustion of fossil fuels is found in the exhaust gas. The gas concentration of these nuclides will be lower than 100 ppm, perhaps lower than 50 ppm, and the production rate will be lower than 0.2% / ton. These pollutants need only be controlled with the appropriate combustion settings.

  Treatment techniques for reducing gas emissions are basically limited to the proper selection of ignition fuel and raw materials, furnace design and operation. US Pat. No. 5,053,210, issued to Michael Buxel et al. On October 1, 1991, describes a flue gas purification method and apparatus. In particular, flue gas is desulfurized and NOx removed by multi-stage adsorption and catalytic reactions in a gravity flow moving bed of particulate carbon support material. The particulate carbon support material is in contact with a lateral stream of gas, and the gravity flow moving bed includes at least two moving beds arranged in series with respect to the gas path. NOx removal occurs in the second or any downstream moving bed. When large quantities of flue gas from industrial furnaces must be purified, the purification is adversely affected by the formation of gas streaks with greatly varying sulfur dioxide concentrations. This disadvantage is that the pre-purified flue gas leaving the first moving bed and having a locally variable sulfur dioxide concentration gradient undergoes repeated mixing prior to the addition of ammonia as a reactant for NOx removal. This is solved.

  US Pat. No. 5,636,240 issued June 3, 1997 to Jeng-Syan et al. Relates to a method and apparatus for controlling air pollution in a glass furnace used at the exhaust outlet of the furnace. This is because the exhaust gas is passed through the spray-type neutralization tower, the sulfate is removed by an absorbent (NaOH) spray that reduces the opacity of the exhaust gas, and the spray-type neutralization tower and the bag using the pneumatic powder supply device. Periodically supplying fly ash or calcium hydroxide to the passage between the house and maintaining the normal function of the filter bag in the bag house.

Finally, to burn pulverized petroleum coke or dust petroleum coke, a special type of burner design needs to be considered. In general, ignition energy is applied to the combustible fuel-air mixture to ignite the burner flame. Several burner systems have been developed to burn pulverized fuel as coal or petroleum coke.

  Uwe Wiedmann et al., PCT / EP83 / 00036, issued September 1, 1983, describes a burner for powder, gas, and / or liquid fuels. The burner has an ignition chamber with a wall that opens rotationally and an exhaust pipe connected to it. In the center of the chamber wall, a pipe inlet for receiving a fuel jet and an air supply portion surrounding the inlet for receiving a vortex of combustion air are arranged. Inside the ignition chamber, a hot recirculation stream is created that mixes the fuel jet and heats it to the ignition temperature. The amount of vortex air supplied to the ignition chamber is only a fraction of the total combustion air required. A second air receiving tube is provided in the area between the chamber wall and the exhaust tube, and another portion of the combustion air is introduced into the ignition chamber and mixed completely or partially with the fuel jet. The sum of the portion of the combustion air involved in the ignition chamber in the mixture with the fuel jet (and thus in the ignition and initiation of combustion) is adjusted so that it does not exceed 50% of the required combustion air. Combining all these means provides a burner that is particularly suitable for heat generation for industrial processing. The burner further has an intermediate and variable power ratio for stable ignition with an elongated configuration that forms a flame in the combustion chamber with less radial deviation of the particles.

  U.S. Pat. No. 4,412,810, issued November 1, 1983 to Akira Izuha et al., Relates to a pulverized coal burner capable of performing combustion in a stable state. The amount of NOx, CO, and unburned carbon produced as a result of combustion is reduced.

  On July 30, 1985, William H. U.S. Pat. No. 4,531,461 issued to Sayler relates to a system for pulverizing solid fuel, such as coal and other fossil fuels, and combusting the pulverized fuel floating in an air stream. This is mainly combined with industrial furnaces used to heat gypsum furnaces and metallurgical furnaces.

  U.S. Pat. No. 4,602,575 issued July 29, 1986 to Klaus Grethe relates to a method of burning petroleum coke dust in a burner flame with a concentrated internal recirculation zone. This petroleum coke dust is fed to a region of the intensive internal recirculation zone where ignition energy is provided for the burned petroleum coke dust. However, according to the description of this patent, petroleum coke can contain harmful substances such as vanadium, depending on the type of treatment the crude oil has undergone. This not only becomes a corrosive compound during combustion in the steam generator, but also considerably pollutes the environment when exiting the “steam generator” along with the flue gas. When this burner is used, these adverse or harmful products can be largely prevented by adding vanadium binding additives to the combustion section via incremental air.

  Another development for coal burners was made on May 15, 1990 by Dennis R. Illustrated in US Pat. No. 4,924,784 issued to Lennon et al. This relates to the ignition of pulverized solvent refined charcoal in a burner for “boilers etc.”.

  Finally, US Pat. No. 5,829,367, issued to Hideaki Ohta et al. On November 3, 1998, relates to a burner for burning pulverized coal mixtures having two concentrations, high and low. In this burner, the height of the burner panel is reduced, and the entire burner is simplified. These burners are applied to boiler furnaces or chemical industry furnaces.

  As noted above, developments are focused on controlling petroleum coke pollution, but these are concentrated on petroleum coke desulfurization or decontamination.

  On the other hand, even though petroleum coke is already used in other industries, the same products that absorb polluted gases may have vanadium erosion and wear effects on the furnace (see Cement Industry). thing).

  In any case, pollution problems and their solutions depend on the industry. Each industry and furnace has various thermal properties and contaminant issues. There are also problems with the type of refractory (which also affects energy consumption and product quality), furnace construction, and the resulting product.

  Despite all the above, the glass industry still considers all the above factors such as pollution, which adversely affects the refractory structure of the furnace and causes serious environmental problems, as well as high sulfur and vanadium contents. On the other hand, the combustion of petroleum coke to melt the glass raw material is not considered.

  Considering all the above methods, the present invention relates to the use of low cost solid fuel derived from petroleum distillation residue (petroleum coke). This makes it possible to produce commercial glass in an environmentally clean manner, reduce the risk of damage to refractories in the glass furnace, and reduce emissions of pollutants in the atmosphere. As described in the background art, since this solid fuel has the above-mentioned problems, it is not considered to be used for melting a glass material.

  Combustion equipment has been developed to supply and burn petroleum coke for efficient combustion for use in the present invention. The present invention also considers an emission control system. This system is placed after the furnace to clean flue gases and prevent the emission of fuel-derived impurities such as SOx, NOx, and particulates. By integrating the developed equipment and selecting the right configuration of equipment and systems, it is possible to use low-cost fuels, produce commercial glass, and generate flue gas within environmental regulations.

  In view of the above, the present invention relates to the design of several systems that are arranged in a single process to produce commercial glass in a side port glass furnace. Therefore, in the side port type glass melting furnace, a powder fuel of the type consisting of carbon, sulfur, nitrogen, vanadium, iron and nickel is burned to melt the glass raw material for producing the plate glass or the glass container. A means for supplying pulverized fuel is disposed in each of a plurality of ports including a first side port and a second side port in the glass melting region of the glass melting furnace to burn the pulverized fuel during the glass melting cycle. Provided in at least one burner. The glass melting furnace includes refractory means. The refractory means withstands the erosion action of the molten glass, the corrosive action of the combustion gas in the regeneration chamber of the glass melting furnace, and the wear force of the particles in the atmosphere caused by the combustion of the powdered fuel in the furnace. Finally, the present invention includes means for controlling air pollution at the exhaust gas outlet after the pulverized fuel in the glass melting furnace is combusted. This measure controls air pollution and reduces sulfur, nitrogen, vanadium, iron and nickel emissions in the atmosphere.

  Furthermore, it is necessary to have at least 98% magnesium oxide to reduce or prevent the risk of damage to magnesium oxide. In this case, the purity of the raw material forming the refractory reduces the amount of calcium oxide present in the raw material and delays the formation of the molten phase. This refractory with impurities surrounded by magnesium oxide needs to be sintered at a high temperature where a ceramic bond is created in the main material.

  A basic refractory with 98% or more magnesium oxide is often used in the top row of the regeneration chamber of a glass melting furnace. Another example of a refractory that can be used in the regeneration chamber or top checker is a zircon-silica-alumina electroformed material. It also exhibits an acidic behavior similar to vanadium pentoxide that reduces the effects of damage to the refractory.

  By properly selecting the refractory in the glass furnace based on the thermodynamic analysis of impurities, the chemical composition of the impurities, and the compounds forming the refractory, the influence of impurities contained in the fossil fuel can be reduced.

  Such an invention has been described in connection with a particular type of furnace. However, it has been found that the use of an actual burner requires the use of a second air that is mixed with a mixture of pulverized fuel and air or gas. All of these lead to heat loss during the combustion cycle. As a result, the efficiency of the burner is reduced.

  Applicant believes that the heat loss is due to the inflow of cold air used for cooling. As a result, the amount of pulverized fuel consumption is slightly increased, and the amount of CO gas generated after combustion increases.

  According to the present invention, a first object is to provide a glass melting method for supplying a mixture of pulverized fuel and air or gas to each of a plurality of burners in a glass melting region of a glass melting furnace in a controlled manner. There is. Thereby, the burner can be operated in an alternate operation cycle of a combustion cycle and a non-combustion cycle.

  It is a further object of the present invention to provide a glass melting method that reduces the cost of melting.

  It is a further object of the present invention to provide a glass melting method that provides optimum mixing in a mixture of pulverized fuel and air or gas. Thereby, CO gas produced as a result of combustion can be reduced.

  Another advantage of the present invention is that it provides a glass melting method in which the effects of erosion and wear of pulverized fuel in the glass melting furnace are reduced.

  Another object of the present invention is to provide a glass melting method in which a mixture of pulverized fuel and air or gas is injected at high speed into each of the burners.

It is a further object of the present invention to provide a glass melting method that uses a special refractory to constitute the glass melting furnace chamber. This reduces the effects of erosion and wear caused by the combustion of the pulverized fuel, in particular, the effects caused by the metals V ₂ O ₅ , Fe ₂ O ₃ , FeO, and NiO contained as contaminants in the solid fuel. Is done.

  It is a further object of the present invention to provide a glass melting method in which pulverized fuel is fed directly to the glass melting furnace as associative fuel-air with about 16% excess of air relative to stoichiometric air.

  Another object of the present invention is to provide a glass melting method in a glass melting furnace that can simultaneously melt two or three types of fuel. A series of burners can be placed in the melting chamber to independently burn petroleum coke, gas or heavy oil.

  Another object of the present invention is to provide a glass melting method in which highly associated solid-air is supplied to pulverized fuel by pneumatic means.

  These and other objects and disadvantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention shown in the accompanying drawings.

It is a block diagram of the Example of this invention. Mainly caused by a system in which pulverized fuel is supplied and burned in at least one burner of a glass melting furnace, erosion of molten glass, corrosive action of combustion gas, and combustion of the pulverized fuel in the furnace Various shapes of refractory means to form the walls and floors of glass melting furnaces to withstand the wear force of particles in the atmosphere, and environmental control system to control air pollution at the exhaust gas outlet after combustion of pulverized fuel in the furnace Including. FIG. 3 shows another block diagram of the first embodiment of the system for supplying and burning petroleum coke according to the present invention. It is a top view of a regenerative type glass melting furnace. It is the schematic of the longitudinal direction of the furnace shown in FIG. 1 is a schematic view of a system for supplying and burning a pulverized fuel according to the present invention. 1 is a side view of a system for supplying and burning pulverized fuel in combination with a regenerative glass melting furnace. It is detail drawing of the arrangement | sequence of the burner which supplies and burns the pulverized fuel which concerns on this invention. FIG. 8 is a side view obtained from FIG. 7 in a preferred embodiment of a burner for burning powdered petroleum coke according to the present invention. It is a front view obtained from FIG. FIG. 9 is a detailed vertical sectional view of the burner of FIG. 8. 1 shows a burner according to the present invention. It is the top view obtained from the "AA" line of FIG. 2 shows a burner with two outlet nozzles.

  The invention will now be described in connection with specific embodiments. Here, the same members are referred to by the same numerals. FIG. 1 is a block diagram of an embodiment of the present invention, which mainly includes a system for supplying pulverized fuel and burning it in at least one burner A of a side port type glass melting furnace, as will be described later. . The refractory means B, which are formed in various shapes, include the walls, floors, roofs of glass melting furnaces, the walls, floors, roofs of different combustion ports where one or more burners are arranged, and the checkers of the regeneration chamber. Form walls, roofs, and Empireage. The refractory means is selected from silica, alumina, zircon, magnesite, chromium, ceramic, alumina-silicic acid, zircon-silicic acid, magnesium oxide, or mixtures thereof. For example, the refractory material may be molded silica, fused silica, directly cast silica; electroformed alumina-silica-zircon; extruded alumina-silica-zircon or directly cast alumina-silica-zircon; electroformed alumina (90-100%), Implanted alumina (90-100%), direct cast alumina (90-100%); electroformed magnesite-alumina spinel, extruded magnesite-alumina spinel, direct cast magnesite-alumina spinel; electroformed magnesite-zircon-silica , Implanted magnesite-zircon-silica, Direct cast magnesite-zircon-silica; Electroformed alumina-silicic acid, Impressed alumina-silicic acid, Direct cast alumina-silicic acid; Electroformed zircon-silicic acid, Impressed zircon-silicic acid , Direct casting zircon-silicic acid; stamping direct bond 98% oxidation Gnesium, pressed ceramic bonded 98% magnesium oxide, direct casting 98% magnesium oxide; pressed direct bonded 90-95% magnesium oxide; pressed ceramic bonded 90-95% magnesium oxide; pressed direct bonded chromium (5-25%)-magnesite (50-85%); molded ceramic bonded chrome (5-25%)-magnesite (50-85%); or directly cast chrome (5-25%)-magnesite (50-85%).

  Another material that can be used on the walls, roofs and floors of glass melting furnaces at temperatures as high as 1350-1450 ° C. is the zircon-silica-alumina electroformed material. It also exhibits an acidic behavior similar to vanadium pentoxide that reduces the effects of damage to the refractory. Another type of refractory material that can be used is selected from materials containing about 80% magnesia and about 20% zirconium silicate. The material is used to withstand the erosion power of molten glass, the corrosive action of combustion gases, and the abrasion power of particles in the atmosphere generated by in-furnace combustion of pulverized fuel (petroleum coke). Finally, an environmental control system C is required to control air pollution at the exhaust gas outlet after combustion of the pulverized fuel in the furnace.

  Different fuels can be suitably used in glass melting furnaces operated with pulverized fuels such as petroleum coke as described in connection with the present invention. In the sidewalls and furnace chest wall, electroformed or directly cast alumina-zircon-silica material is used to provide chemical resistance to glass, carryover and alkaline volatiles, and heavy metal contaminants in pulverized fuel. Also, other materials such as high alumina can be used for the last port of the side port furnace where carryover is not found because the batch and foam are already melted. In the manufacturing process, different materials undergo electroforming, stamping or direct casting. In addition, the chemical resistance of the refractory increases due to the inclusion of high alumina and low calcium. This reduces the chemical reaction between heavy metals such as vanadium and calcium silicate, which is a binder used in refractories. In the refining zone of the melting furnace where there is no flame, silica material is suitable for the chest wall and the furnace front and gable walls. Alumina-zircon-silica, high alumina, magnesia-alumina spinel refractories can be used for walls, floor ports, and port crowns.

  It should be noted that different processes such as electroforming, stamping, and direct casting can be applied to make the refractory, depending on the appropriate material.

  Chromium-magnesite, magnesite, and magnesite-zircon-silicic acid at the top regenerator wall and crown provide good chemical resistance to cope with heavy metals found in pulverized fuels such as petroleum coke Different materials such as materials are also suitable. Silica is often used in crown regenerators and is recommended.

  For the top checker, alumina-zircon-silica electroformed materials, and magnesite, chromium-magnesite, and magnesite-zircon-silicic acid are considered suitable. It is also considered chemically suitable to cope with all of the different compounds arising from glass operation and from heavy metal glasses of pulverized fuel such as petroleum coke.

  In the lower checker where the temperature is low and the chemical environment is not aggressive, the following refractories are considered convenient for operation. Implant direct bond 98% magnesium oxide, Implant ceramic bond 98% magnesium oxide, direct casting 98% magnesium oxide; Implant direct bond 90-95% magnesium oxide; Implant ceramic bond 90-95% magnesium oxide; Direct casting 90-95% oxidation Magnesium; Implant direct bonded chromium (5-25%)-magnesite (50-85%); Impressed ceramic bonded chromium (5-25%)-magnesite (50-85%); or Direct cast chrome (5-25) %)-Magnesite (50-85%).

  Referring now to FIG. 2, the system (A) for supplying and burning pulverized fuel supplies each burner 48a, 48b, 48c, 48d and 48e to supply pulverized petroleum coke and burn it in a glass melting furnace. 48f, 48g, 48h, and burners 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h (see FIGS. 3 and 5). The system (A) for supplying and burning pulverized fuel includes a combination of a charging system (D) for charging powdered petroleum coke and a combustion system (E) for burning powdered petroleum coke in a glass melting furnace. . The input system (D) can be supplied by a system (F) known in the industry for supplying and handling pulverized petroleum coke.

  A system (A) for supplying and burning pulverized fuel will be described below with reference to FIGS. That is, FIGS. 3 and 4 show schematic views of a regenerative glass melting furnace including a melting chamber 10, a refining chamber 12, a conditioning chamber 14, and a throat 16 between the refining chamber 12 and the conditioning chamber 14. A front furnace connection 20 is provided at the front end 18 of the purification chamber 12. Molten glass is removed from the purification chamber 12 through the forehearth connection 20. A dog house 24 is provided at the rear end 22 of the melting chamber 10. Through the dog house 24, glass raw material is supplied by a batch filler 26. A pair of regenerators 28 and 30 are provided on each side of the melting chamber 10. The regenerators 28 and 30 are provided with ignition ports 32 and 34 for connecting the regenerators 28 and 30 to the melting chamber 10. The regenerators 28 and 30 are provided with a gas regeneration chamber 36 and an air regeneration chamber 38. Both chambers 36, 38 are connected to the lower chamber 40. The lower chamber 40 is configured to communicate with the exhaust gas tunnel 44 and the chimney 46 via the damper 42. Burners 48a, 48b, 48c, 48d, 48e, 48f, 48g, 48h and burners 50a, 50b, 50c, 50d, 50e, 50f, 50g, 50h are natural gas, petroleum coke or other used in glass melting furnaces. In order to burn this type of fuel, each port 32, 34 is disposed in the neck portion 52, 54 of each ignition port 32, 34.

  For this reason, when a glass raw material is supplied to the rear end portion of the melting chamber 10 via the dog house 24, the molten glass is melted by the burners 48a to 48h and 50a to 50h. It then floats forward until it passes from the melting chamber 10 to the conditioning chamber 14 and is completely melted. During the operation of the furnace, the regenerators 28 and 30 are alternately switched between the combustion air cycle and the exhaust cycle. Depending on the specific furnace, every 20 or 30 minutes, a series of burner 48a-48h or 50a-50h flame passages are switched. For this reason, the flames and combustion products generated in each of the burners 48 a to 48 h and 50 a to 50 h pass through the entire surface of the molten glass and transfer heat to the glass in the melting chamber 10 and the purification chamber 12.

Supply of powdered petroleum coke (F)
5 and 6, the system (A) for supplying and burning the pulverized fuel in the glass melting furnace is the powder used in the glass melting furnace in the first embodiment of the present invention. A first storage silo or tank 56,58 is provided for storing body petroleum coke or other types of fuel. The storage silos 56 and 58 are supplied from the wagon or the wagon train 60 via a first inlet pipe 62 connected between the wagon train 60 and the silos 56 and 58. The first main pipe 62 has first branch pipes 64 and 66 connected to the silos 56 and 58 to fill the silos 56 and 58, respectively. Valves 68 and 70 are connected to the first branch pipes 64 and 66 in order to control the filling amount of the silos 56 and 58. Each silo 56, 58 is filled by the vacuum action of the vacuum pump 70 via the first outlet pipe 72. The first outlet pipe 72 has second branch pipes 74 and 76 connected to the respective silos 56 and 58. Valves 78 and 80 are connected to the respective second branch pipes 74 and 76 in order to control the vacuum action caused by the vacuum pump 70 filling each silo 56 and 58.

  At the bottom of each silo 56, 58 are provided conical portions 82, 84 and gravimetric coke supply systems 86, 88. These fluidize the powdered petroleum coke to ensure a constant discharge flow into the second outlet pipe 90. Here, the powder material is sent to the solid fuel charging systems SD-5, SD-6, and SD-7. The second outlet pipe 90 includes third branch pipes 92 and 94 connected to the bottoms of the conical parts 82 and 84 of the respective silos or tanks 56 and 58. Valves 96 and 98 are attached to the respective third branch pipes 92 and 94 in order to control the flow of the powdered petroleum coke to the second outlet pipe 90.

Powdered petroleum coke charging system (D)
Referring now to the charging system (D) according to the present invention, the pulverized petroleum coke is received by the solid fuel charging systems SD-5, SD-6 and SD-7 via the second outlet pipe 90. The fourth branch pipes 100, 102, and 104 are connected to the second outlet pipe 90, and the powder coke in the first silo or tanks 56, 58 is transferred to the solid fuel supply systems SD-5, SD-6, SD-7. Is done. Each solid fuel supply system SD-5, SD-6, SD-7 includes a second series of silos or tanks 106, 108, 110. A second series of silos or tanks 106, 108, 110 are provided with conical sections 112, 114, 114 to release a constant coke flow toward each of burners 48f, 48g, 48h and burners 50f, 50g, 50h. 116, gravimetric coke supply systems 118, 120, 122, aeration systems 124, 126, 128, feeders 130, 132, 134, and filters 136, 138, 140.

  The air compressor 142 and the air tank 144 are connected by the second main pipe 146. First inlet branch pipes 148, 150, 152 are connected to second main pipe 146 to supply filtered air (through filters 136, 138, 140). This causes the coke to be transferred into each of the second series of silos or tanks 106, 108, 110. The second main pipe 146 also includes first return branch pipes 154, 156, 158 connected to the aeration systems 124, 126, 128. The first return branch pipes 154, 156, 158 allow for proper coke flow to the third outlet pipes 160, 162, 164. This will be described later. Further, a second inlet pipe 166 is connected to the second main pipe 146 (after the air tank 144). The second inlet pipe 166 includes second inlet branch pipes 168 and 170 connected to the upper portions of the respective silos or tanks 56 and 58. The second inlet branch pipes 168 and 170 inject air into the respective silos or tanks 56 and 58.

  The solid fuel supply systems SD-5, SD-6, and SD-7 include fourth outlet pipes 172, 174, and 176 connected to the lower portions of the feeders 130, 132, and 134, respectively. Three-way regulating valves 178, 180, and 182 are connected to the fourth outlet pipes 172, 174, and 176 on the first direction side. The second direction side is connected to the first return pipes 179, 181, 183 to return excess powder coke to each of the second series of silos or tanks 106, 108, 110. The third direction side is connected to the third outlet pipes 160, 162, 164. Third outlet tubes 160, 162, 164 are used to supply an air-fuel mixture to a predetermined array of four-way tubes 184, 186, 188 associated with the combustion system (E) described below.

Combustion system (E)
Referring now to the combustion system (E), it is connected to each solid fuel supply device SD-5, SD-6, SD-7 via the first direction side of four-way tubes 184, 186, 188. The The four-way pipes 184, 186, 188 are connected to the third outlet pipes 160, 162, 164 of the solid fuel supply devices SD-5, SD-6, SD-7. The second direction side is connected to each of the fourth outlet pipes 190, 192, 194 and supplies the supply air-fuel mixture to the burners 48h, 48g, 48f. The third direction side of the four-way pipes 184, 186, 188 is connected to the fifth outlet pipes 196, 198, 200 to supply the air-fuel mixture to the burners 50h, 50g, 50f. The fourth direction side of the four-way tubes 184, 186, 188 is connected to the second return tubes 202, 204, 206 to pass excess powder coke to each of the second series of silos or tanks 106, 108, 110. return. The four-way pipes 184, 186, 188 and the four-way pipes 184, 186, 188 and the fourth outlet pipes 190, 192, 194, the fifth outlet pipes 196, 198, 200, and the second return pipes 202, 204, 206, Are connected to ball valves 208A to 208C, 210A to 210C, and 212A to 212C.

  Thus, during furnace operation, the burners 48a-48h or 50a-50h are alternately switched between the combustion cycle and the non-combustion cycle. Depending on the particular furnace, every 20 or 30 minutes, a series of burner 48a-48h or 50a-50h flame paths are reversed. The air-fuel mixture reaching through the third outlet pipes 160, 162, 164 is controlled by the four-way pipes 184, 186, 188 and ball valves 208A-208C, 210A-210C, 212A-212C, and burners 48a-48h. And the burner 50a to 50h are switched to inject the air-fuel mixture. When alternating cycles between burners 48a-48h and burners 50a-50h are performed, a predetermined amount of air-fuel mixture is transferred to second series of silos or tanks 106, 108 via second return pipes 202, 204, 206. , 110.

  The supply air supplied through the third outlet pipes 160, 162, and 164 is used to transfer petroleum coke and perform coke injection at high speed toward the nozzles of the burners 48a to 48h and 50a to 50h. Supply air is supplied by the pneumatic supply air blower 214 via the third main pipe 216.

  The fourth outlet pipes 218, 220, and 222 are connected to the second main pipe 216 and the third outlet pipes 160, 162, and 164, and the high degree of association of the fuel-air mixture supplied to the burners 48a to 48h and 50a to 50h is maintained. Is done.

  To enable the burner 48a-48h or 50a-50h combustion cycle, each burner 48a-48h or 50a-50h is individually supplied with an air-fuel mixture. This mixture is fed through the inner tube of each burner 48a-48h or 50a-50h to reach the distribution chamber and is distributed to the various injection nozzles of each burner 48a-48h or 50a-50h.

  In each burner 48a-48h or 50a-50h, primary air is injected from the primary air blower 224 to increase the disturbance of the mixture and flow of pulverized fuel and preheated combustion air. Primary air is supplied under pressure through the spray nozzles of each burner 48a-48h or 50a-50h. For this reason, the operation of the burners 48a to 48h or 50a to 50h includes coke injection by pneumatic transfer. Pneumatic transfer involves highly associated solid-air with primary air of about 4% of stoichiometric air.

  A sixth outlet pipe 226 and a seventh outlet pipe 228 are connected to the primary air blower 224. The sixth outlet pipe 226 is connected to the fifth branch pipes 230, 232 and 234, and the seventh outlet pipe 228 is connected to the sixth branch pipes 236, 238 and 240. The outlet ends of the fifth and sixth branch pipes 230, 232, 234, 236, 238, and 240 are directly connected to the burners 48f to 48h or 50f to 50h, respectively. The primary air flows of the fifth and sixth branch pipes 230, 232, 234, 236, 238, and 240 are individually controlled by the first globe valve 242, the first ball valve 244, and the second globe valve 246 in a predetermined arrangement. Controlled.

  Further, the sixth outlet pipe 226 includes seventh outlet pipes 248, 250, 252. The seventh outlet pipes 248, 250, 252 are connected to the fifth outlet pipes 196, 198, 200, respectively. The seventh outlet pipe 228 includes sixth outlet pipes 254, 256 and 258. The sixth outlet pipes 254, 256, and 258 are connected to the fourth outlet pipes 190, 192, and 194, respectively. Each of the sixth and seventh outlet pipes 248, 250, 252, 254, 256, 258 includes a check valve 260 and a ball valve 262.

  Due to the arrangement described above, the primary air blower 224 supplies primary air to the fifth and sixth branch pipes 230, 232, 234, 236, 238, 240 via the sixth outlet pipe 226 and the seventh outlet pipe 228. Supply to burners 48f-48h (left burner) or burners 50f-50h. The air blower 224 operates to provide maximum air flow during operation of each burner 48f-48h or burner 50f-50h, while each non-operating burner 48f-48h or burner 50f-50h has a sixth and a sixth A minimum air flow is provided for every seven outlet pipes 248, 250, 252, 254, 256, 258. This ensures better cooling conditions.

  Although the present invention has been described based on three burners 48f, 48g, 48h and burners 50f, 50g, 50, it will be understood that the system described in the present invention applies to all burners 48a-48h and 50a-50h. Should.

  In additional embodiments of the present invention, glass melting can be performed with two or three types of fuel. For example, in FIG. 3, pulverized fuel such as petroleum coke can be supplied to the burners 48a to 48d and 50a to 50d, and gas or heavy oil can be supplied to the burners 48e to 48h and 50e to 50h. In the third embodiment of the present invention, pulverized fuel such as petroleum coke can be supplied to the burners 48a to 48d and 50a to 50d. Gas can be supplied to the burners 48e to 48f and 50e to 50f. Heavy oil can be supplied to the burners 48g to 48h and 50g to 50h. These combinations take into account that there are already glass melting furnaces today that use gas or heavy oil as the primary fuel for the purpose of glass melting, and that the behavior of these gases and heavy oil is well known in the prior art. It is.

Powdered fuel burners In addition, special burners have been designed for use in systems that supply pulverized fuel and burn it in a glass melting furnace for good combustion of powdered petroleum coke. 7 to 12 show detailed views of a burner (48f) for supplying and burning pulverized fuel according to the present invention. The pulverized fuel burner (48f) includes a body 264 composed of an outer tube 266, an intermediate tube 268, and an inner tube 270 (FIG. 10) arranged concentrically with each other. The outer tube 266 is sealed at the upper end 272 (FIG. 9). A first chamber 276 is formed in the space defined by the outer tube 266 and the intermediate tube 268. The outer tube 266 has an inlet tube 278 and an outlet tube 280 (FIG. 8). Through these, cooling water is introduced into the first chamber 276 to cool the burner (48f). The intermediate tube 268 and the inner tube 270 extend beyond the upper end 272 of the outer tube 266.

  An air inlet pipe 282 is connected to the upper part of the burner 48 f so as to be inclined around the intermediate pipe 268. The air inlet pipe 282 is connected to the sixth branch pipe 236 (see FIG. 7), and the flow of primary air or natural gas flows into the second chamber 284 formed in the space defined by the inner pipe 270 and the intermediate pipe 268. be introduced. The second chamber 284 serves to guide primary air or natural gas from the air inlet pipe 236 (see FIG. 7). Primary air or natural gas is conveyed to the lower end of the burner 48f. The primary air flow in the second chamber 284 is controlled by the arrangement of the first globe valve 242, the first ball valve 244, and the second globe valve 246.

  Similarly, a mixture of secondary air and powdered petroleum coke is introduced from the upper end 286 of the inner pipe 270 and conveyed to the lower end of the burner 48f. The upper end 286 of the inner pipe 270 is connected to the fourth outlet pipe 194, and the supplied pulverized fuel-secondary air mixture is supplied to the burner (48f). Therefore, when the primary air and the secondary air-powder petroleum coke mixture reach the lower end of the burner (48f), the primary air or natural gas and the pulverized fuel-secondary air mixture are mixed, Ignite the combustion process described in.

  Referring now to FIGS. 10-12, these are detailed views of a burner (48f) for supplying and burning pulverized fuel according to the present invention.

  Basically, the burner (48f) (FIG. 10) includes a body 264 consisting of an outer tube 266, an intermediate tube 268, and an inner tube 270 (FIG. 10) arranged concentrically with each other. A first chamber 276 is formed in the space defined by the outer tube 266 and the intermediate tube 268. The outer tube 266 has an inlet tube 278 and an outlet tube 280. Through these, cooling water is introduced into the first chamber 276 to cool the burner (48f).

  With particular reference now to FIGS. 10-11, the lower end 274 of the burner (48 f) includes a flow distributor 286. It accepts and distributes a mixture of pulverized fuel and air or gas. The gas is natural gas or oxygen. A flow distributor 286 (FIG. 11) is connected below the lower end 274 of the burner (48f). The flow distributor 286 includes a body 288 that defines a first distribution chamber 290 that receives a mixture of pulverized fuel and air or gas, and a second chamber 292 that surrounds a portion of the first distribution chamber 290. Through the second chamber 292, cooling water for cooling the burner (48f) is introduced.

  The flow distributor 286 also includes a discharge end 294 disposed at a 90 ° position relative to the body 288. This deflects the flow of the mixture of pulverized fuel and air or gas from a vertical flow to a longitudinal flow. The discharge end 294 includes a passage 296 (FIG. 10). This is formed longitudinally in the body 286 and connects the first distribution chamber 290 to the outer periphery of the body 286. The passage 296 is formed by the first inner annular portion 298. Through this, a mixture of pulverized fuel and air or gas flows. The inside of the first annular portion 298 is formed in a truncated cone shape whose diameter decreases toward the front of each passage. Further, the second intermediate annular portion 300 surrounds the first inner annular portion 296 through which a mixture of pulverized fuel and air or gas flows. First inner annular portion 298 and intermediate annular portion 298 define an inlet for receiving nozzle 302. The nozzle 302 supplies a mixture of pulverized fuel and air or gas in a glass melting furnace chamber. Finally, the periphery of the body 288 and the second annular portion 308 define a third chamber 294 for flowing water for cooling the burner (48f).

  Referring now to the nozzle 302, the nozzle includes a cylindrical head 304 and a cylindrical member 308 disposed in alignment with the rear of the head 304.

  In the second embodiment of the burner (FIG. 11), the flow distributor 286 is shown with two discharge ends 310, 312 positioned at 90 ° relative to the body 288. A nozzle 302 is introduced by each discharge end 310, 312. The positions of the discharge ends 310, 312 are spaced from each other at an angle of about 10 ° to about 20 ° with respect to the longitudinal axis 314.

  Here, according to the burner (48f) shown in FIGS. 8 and 10, a mixture of air or gas and powdered petroleum coke is introduced through the inner pipe 270 and sent to the first distribution chamber 290. The mixture then flows from this portion into the passage 296 of the flow distributor 286. The mixture is fed axially through passage 296 to be introduced into the chamber of the glass melting furnace.

  Cooling water is continuously introduced through the first chamber 270 and the third chamber 292 to cool the burner.

  Although the burner (48f) has been described as being cooled by water, burners that do not necessarily require cooling as described in International Application No. PCT / MX2006 / 000094 can also be used.

  A method for supplying pulverized fuel and burning in a glass melting furnace as described above, wherein the glass melting furnace includes a glass melting region lined with a refractory material, and a plurality of burners associated with the glass melting furnace. This method includes:

  Supplying a pulverized fuel containing fixed carbon and impurities composed of sulfur, nitrogen, vanadium, iron and nickel or a mixture thereof to each of the burners relating to the closed regenerator of the glass melting furnace. The pulverized fuel is fed directly into the furnace as associative fuel-air with about 16% excess of air over stoichiometric air.

  Combusting the pulverized fuel for each of the burners in the melting region of the melting furnace. A flame is given to each burner and a combustion process is performed in the melting region to melt the glass.

  The environmental control means controls the emission of carbon and impurities generated by the combustion of the pulverized fuel. The environmental control means is placed at the exhaust gas outlet of the glass melting furnace, purifies the flue gas, and reduces the emission of impurities from the pulverized fuel such as SOx, NOx and fine particles. The emission reduction is controlled during and after completion of pulverized fuel combustion in the glass melting furnace.

  To weaken the erosion and wear of pulverized fuel in the glass melting furnace by refractory means. The glass melting furnace is constituted by the refractory means to control the erosion action and the wear action caused by the combustion of the pulverized fuel in the furnace.

  The method also includes the following steps.

  Supplying a controlled flow of a mixture of pulverized fuel and air or gas under pressure for pneumatic transfer in at least one distribution means.

  Discharging a mixture of pulverized fuel and air or gas from a supply means towards the at least one distribution means;

  Adjusting the mixture of pulverized fuel and air or gas directed from the distribution means to each of the plurality of burners in the glass melting region of the glass melting furnace in a controlled manner.

  Burning the pulverized fuel by the burner in the glass melting region of the glass melting furnace while providing a combustion flame with high thermal efficiency to perform controlled heating for melting the glass.

  And the step of weakening the erosion and wear action of the pulverized fuel in the glass melting furnace by the refractory material.

  In addition, the method comprises operating the burner in an alternating cycle of combustion and non-combustion cycles and returning the flow of the mixture of pulverized fuel and air or gas from the distribution means to the supply means while And performing the alternating operation cycle.

Environmental control Finally, after burning pulverized fuel in a glass melting furnace, facilities that reduce and control air pollution and emissions of sulfur, nitrogen, vanadium, iron and nickel compounds in the atmosphere are 44 is connected to a chimney 46 for exhaust gas. The pollution control system according to the present invention is applied to an exhaust gas outlet of a glass melting furnace.

  It has been proven that electrostatic precipitators perform good removal of particulate matter in glass furnaces for pollutant emission control. The fine granular material in the glass furnace has no problem with the electrostatic precipitator.

If in addition to the SO ₂ removal particulate matter is required, dry or partially wet scrubber is satisfactorily compensate for the electrostatic precipitator or a fabric filter system. In fact, a scrubber is required to reduce the concentration of the corrosive gas under the conditions of strong acid gas. When using new fuel, a scrubber is required to reduce the SO ₂ content. This not only has an advantageous effect on the corrosion prevention system, but also reduces the temperature of the exhaust gas. For this reason, the gas volume decreases.

Dry scrubbing (dry reaction powder injection) and semi-wet scrubbing are performed in a large reaction chamber upstream of the electrostatic precipitator. In both dry and semi-wet, the scrubbing material includes Na ₂ CO ₃ , Ca (OH) ₂ , NaHCO _{3 and the} like. The resulting reactant is a raw material for the glass manufacturing process and can generally be recycled to some extent. A rule of thumb, for every 1% of sulfur in the fuel, the molten glass per ton SO ₂ occurs approximately 1.81 kg (4 lbs). For this reason, there is a large amount of dry waste such as NaSO ₄ for high sulfur fuel. The amount of waste varies depending on the capture rate and the amount of material that can be recycled, but the number is significant. For a float furnace operated with high sulfur fuel, the waste can be as much as 5 tons per day.

The level of scrubbing performance varies from 50% to 90% using dry NaHCO ₃ or half wet Na ₂ CO ₃ . Temperature control is important in all scrubbing selected with a target reaction temperature in the range of about 250 ° C. to 400 ° C. in the scrubbing material.

The number of wet scrubber shapes, dimensions, and applications is almost infinite. There are two main applications for glass production, one for collecting gas (SO ₂ ) and the other for capturing particulate matter.

  As described above, a system has been described in which pulverized fuel is supplied and burned in at least one burner of a glass melting furnace, but many other features or improvements that are considered to be within the scope determined by the claims are possible. It will be apparent to those skilled in the art.

Claims (30)

A method of burning a pulverized fuel as a heat source to melt a raw material for manufacturing glass,
a) supplying a controlled flow of a mixture of pulverized fuel and air or gas under pressure for pneumatic transfer in at least one distribution means;
b) releasing a mixture of said pulverized fuel and air or gas from a supply means towards said at least one distribution means;
c) adjusting the mixture of the pulverized fuel and air or gas directed from the distribution means to each of a plurality of burners in a glass melting region of a glass melting furnace in a controlled manner;
d) burning the pulverized fuel with the burner in the glass melting region of the glass melting furnace while providing a combustion flame with high thermal efficiency to perform controlled heating for melting the glass;
e) reducing the erosion and wear action of the pulverized fuel in the glass melting furnace with a refractory material;
The method wherein the refractory material is silica-alumina-zircon, magnesite, chromium-magnesite, magnesia-alumina spinel, alumina-silicic acid, zircon-silicic acid, magnesium oxide, or a mixture thereof.   The method of claim 1, wherein the refractory material is extruded silica.   The method of claim 1, wherein the refractory material is fused silica.   The method of claim 1, wherein the refractory material is directly cast silica.   The method of claim 1, wherein the refractory material is electroformed alumina-silica-zircon.   The method of claim 1, wherein the refractory material is a stamped alumina-silica-zircon.   The method of claim 1, wherein the refractory material is directly cast alumina-silica-zircon.   The method of claim 1, wherein the refractory material comprises about 90-100 wt% electroformed alumina.   The method of claim 1, wherein the refractory material comprises about 90-100 wt% stamped alumina.   The method of claim 1, wherein the refractory material comprises about 90-100 wt% direct cast alumina.   The method of claim 1, wherein the refractory material is an electroformed magnesite-alumina spinel.   The method of claim 1, wherein the refractory material is an extruded magnesite-alumina spinel.   The method of claim 1, wherein the refractory material is a direct cast magnesite-alumina spinel.   The method of claim 1, wherein the refractory material is electroformed magnesite-zircon-silica.   The method of claim 1, wherein the refractory material is stamped magnesite-zircon-silica.   The method of claim 1, wherein the refractory material is directly cast magnesite-zircon-silica.   The method of claim 1, wherein the refractory material is electroformed alumina silicic acid.   The method of claim 1, wherein the refractory material is stamped alumina silicic acid.   The method of claim 1, wherein the refractory material is directly cast alumina silicic acid.   The method of claim 1, wherein the refractory material is electroformed zircon-silicic acid.   The method of claim 1, wherein the refractory material is stamped zircon-silicic acid.   The method of claim 1, wherein the refractory material is direct cast zircon-silicate.   The method of claim 1, wherein the refractory material is a stamped direct bond comprising at least 98% magnesium oxide.   The method of claim 1, wherein the refractory material is a direct casting comprising at least 98% magnesium oxide.   The method of claim 1, wherein the refractory material is a stamped direct bond comprising about 90% to about 95% magnesium oxide.   The method of claim 1, wherein the refractory material is an extruded ceramic bond comprising about 90% to about 95% magnesium oxide.   The method of claim 1, wherein the refractory material is a direct casting comprising from about 90% to about 95% magnesium oxide.   The method of claim 1, wherein the refractory material is a stamped direct bond comprising about 5% to about 25% chromium and about 50% to about 85% magnesite.   The method of claim 1, wherein the refractory material is an extruded ceramic bond comprising about 5% to about 25% chromium and about 50% to about 85% magnesite.   The method of claim 1, wherein the refractory material is direct casting comprising about 5% to about 25% chromium and about 50% to about 85% magnesite.

Images